KR20110059754A - Medical/surgical powered handpiece for rotating the shaft of a accessory, the handpiece having a coupling assembly that facilitates the fine or coarse adjustment of the extension of the accessory shaft - Google Patents

Abstract

A surgical instrument system comprising a handpiece with a motor and a cutting accessory with a shaft rotated by the handpiece motor. The handpiece includes a coupling assembly having a plurality of locking elements for holding the accessory shaft to an output drive shaft actuated by the handpiece motor. The locking elements are longitudinally spaced apart from each other. In the accessory shaft, stagnation features are formed in which the handpiece locking elements are bound. The shaft stagnation features are in the columns. The stagnation features of adjacent stagnation features are longitudinally offset from each other. This allows for coarse or fine adjustment of the range in which the accessory shaft extends forward from the handpiece engagement assembly.

Description

MEDICAL / SURGICAL POWERED HANDPIECE FOR ROTATING THE SHAFT OF A ACCESSORY, THE HANDPIECE HAVING A COUPLING ASSEMBLY THAT With A Coupling Assembly That Helps Precision Or Rough Adjustment Of Extension Of The Accessory Shaft FACILITATES THE FINE OR COARSE ADJUSTMENT OF THE EXTENSION OF THE ACCESSORY SHAFT}

The present invention generally relates to a surgical tool system to which accessories are selectively attached. More specifically, the present invention provides a complementary accessory that is collectively configured to allow selective, or coarsely set, longitudinally positioning of an accessory relative to a handpiece. accessory) and surgical instrument system.

In modern surgery, one of the most important instruments available to medical personnel is a powered surgical tool. In general, such tools include some type of handpiece in which a motor is housed. The handpiece is secured with accessories designed to be applied to the surgical site of a patient to accomplish a particular medical task. Some powered surgical instruments are equipped with a drill or bur for cutting hard tissue or for selectively removing hard tissue. Another powered surgical tool is equipped with a saw blade as a cutting accessory. These tools are used to separate large sections of hard tissue and / or soft tissue. The ability to use powered surgical instruments on a patient alleviated physical strains of physicians and other medical personnel when performing a procedure on the patient. In addition, most surgical procedures with powered surgical instruments can be performed more quickly and more accurately than manual surgical instruments preceded by powered surgical instruments.

Applicant's assignee's U.S. Patent No. 5,888,200, entitled “MULTI-PURPOSE SURGICAL TOOL SYSTEM” (patented March 30, 1999), incorporated by reference herein, is a surgical tool designed for a number of different applications. Start the system. Such a tool system includes a handpiece in which a motor is accommodated. The handpiece also includes a first coupling assembly for selectively coupling the shaft of the accessory to the motor shaft. Such handpiece also includes a second coupling assembly. The second engagement assembly is used to selectively secure the attachment to the front end of the handpiece. Such attachment may include its own drive shaft and accessory coupling assembly. Such attachments may be elongated attachments, angled attachments and / or actuate saw blades. Thus, the benefits of providing this type of tool system can be used to drive the majority of different cutting accessories and to help position the accessory at the surgical site, in the manner required or desired for the particular surgical procedure.

Popular cutting accessories for use with this type of surgical tool system include drills and burrs. Each of these cutting accessories generally has a head that forms the actual tissue removal member of the accessory. The shaft extends rearward from the head. The shaft is the part of the cutting accessory to which the coupling assembly locks around.

There are limitations associated with such systems. The coupling assembly of such a system is designed such that the cutting accessory can be secured to it only in a single fixed position relative to the handpiece. The disadvantage of this arrangement is that the surgeon frequently finds it useful to have some flexibility in positioning the head of the cutting accessory relative to the handpiece. So far, to provide this flexibility, it is necessary to provide a set of cutting accessories with the same cutting heads. The difference between the accessories is the length of their complementary shafts. When the surgeon wishes to place the head of the accessory relatively close to the handpiece, the surgeon installs a cutting accessory with a relatively short shaft in the handpiece. When the surgeon wishes to distance the head of the accessory from the handpiece, the surgeon installs a cutting accessory with a relatively long shaft in the handpiece.

In addition, during the surgical procedure, the surgeon may wish to use different tools to access different locations at the surgical site. Instead, surgeons have a personal preference as to how they wish to view the surgical site and / or how to handle their surgical instruments. To reconcile these variations, the surgical instrument system is equipped with members that vary only in the geometry and / or dimensions of the components employed to convey the force generated by the handpiece motor to the associated cutting accessory. For example, the tool system described in the aforementioned US Pat. No. 5,888,200 has different length attachments and attachments with straight and angled distal end sections from the associated handpiece housing. If the surgeon must approach a surgical site located close to the patient's skin, the surgeon has an available medium length attachment. Instead, if a surgeon needs to approach a surgical site deep into the patient, the surgeon has a long attachment available. This attachment holds the head of the cutting accessory a relatively long distance from the handpiece as compared to the intermediate length attachment. Angled attachments are also available. This attachment is used to hold the cutting accessory at an angle that is offset with respect to the longitudinal axis of the handpiece. Angled attachments are used to provide the surgeon with an alternative field of view of the surgical site and / or to place the cutting accessory on a surgical site that is difficult to reach.

Clearly, having these different attachments available is beneficial to the surgeon. However, the coupling assemblies inside these attachments are often located at different longitudinal distances from their head ends, their distal ends, the ends where the shaft of the accessory emerges. In order to use these attachments, it is necessary to provide a cutting accessory with the same head but with different length shafts. Accessories with short length shafts fit into attachments where the coupling assemblies are located at relatively short distances from their distal openings. Accessories with long length shafts fit into attachments in which the coupling assemblies are located at longer distances from their distal openings. This is another reason why it is sometimes necessary to have a number of different cutting accessories that can be used in a single surgical procedure that only changes in their shaft length.

Another limitation associated with cutting accessories such as drills and burrs relates to the fact that many different accessories are sometimes packaged in sets. These accessories are so packaged together for use because during the procedure, one can hope to see a complete set of accessories that the surgeon has. Instead, prior to the start of the surgical procedure, a number of individual accessories are each unpackaged and arranged in a set for the surgeon. Again, this is to enable the surgeon to easily access and view many different accessories.

However, often during the procedure, surgeons do not use all of the cutting accessories released from their sterilized packaging. Used accessories are generally discarded. This is because the cutting heads of these accessories are at least partially worn. However, after the procedure, there may be one or more exposed cutting accessories that are not used. These accessories can be used in new procedures if they are sterilized to remove any contamination that may have been picked up as a result of their exposure to the environment before reuse. In the procedure used to sterilize these accessories, they are heated to a temperature of about 132 ° C. and subjected to saturated water vapor at a pressure of 2.1 bar. These accessories are formed of tool steel because the cutting surfaces formed from such material tend to wear on slower speed cutting surfaces formed from stainless steel. In addition, tool steels are cheaper than the alternative material, carbide steel. However, during the above disinfection treatment, the tool steel tends to discolor. This discoloration is embarrassing to medical personnel. Thus, medical personnel are reluctant to use these unused autoclave sterilized accessories, even if their sterilization degree and quality are the same as the accessories just displaced from the manufacturer's packaging. Thus, these unused accessories tend to be discarded, even though they can be used in later procedures with proper sterilization. Disposal of these cutting accessories is a waste of resources even if they are not even used.

Applicant's assignee's US Pat. No. 6,562,055 provides a surgical tool system to which a cutting accessory is selectively attached. The surgical instrument system in the '055 patent includes a specially designed cutting accessory with retention features. As shown in figures 40 and 41 of the '055 patent, the stagnation features consist of cut-outs extending inward from the outer cylindrical wall of the cutting accessory shaft. The cutouts work with a locking mechanism that allows the longitudinal position of the accessory relative to the hand tool to be adjusted. The relative position can be adjusted between the positions defined by the cutouts and the distance between the positions equal to the longitudinal distance between the cut-outs. Thus, in a '055 system, the relative position can only be adjusted as an increase equivalent to this distance. In practice, it has been found that stagnation features need to be spaced at least 2.4 mm apart. If the stagnation features are spaced less apart, the features will be smaller accordingly. Complementary engagement features of the handpiece engagement assembly may then not be able to capture the stagnation features over a surface area large enough to ensure transfer of torque from the handpiece engagement features to the accessory shaft.

The present invention relates to a new and useful surgical tool assembly. The tool assembly of the present invention includes a handpiece with a motor. The motor may be electric or pneumatic. The output drive shaft is connected to the rotor integral with the motor for rotation by the rotor. The coupling assembly releaseably holds the shaft of the cutting accessory to the output drive shaft such that the accessory shaft rotates with the output drive shaft. The coupling assembly includes a plurality of locking elements. The locking elements are arcuately spaced from one another and may be spaced apart from one another along the longitudinal axis of the output drive shaft.

Another aspect of the invention is the geometry of an accessory designed for use with the surgical instrument described above. The accessory includes an elongate shaft, head, and a plurality of stagnation features. The elongate shaft has a distal end, a proximal end, and a longitudinal axis. The head is connected to the shaft at the distal end. The plurality of stagnation features are arranged in columns of the plurality of stagnation features. The columns are arcuately spaced around the accessory shaft. The stagnation features are also aligned such that stagnation features in one column are longitudinally offset relative to stagnation features in adjacent columns.

Using the tool system of the present invention, the distance the accessory shaft extends forward from the coupling assembly can be adjusted by pushing or pulling on the accessory shaft. This movement causes each locking element to continuously confine the stagnation features in a single column of stagnation features. This adjustment will result in adjustment of the shaft by a unit equivalent to longitudinal separation of stagnation features in a single column, rough adjustment of shaft extension / retraction. Instead, the accessory shaft extension / retraction can be adjusted by rotating the accessory shaft. This action results in each cutting accessory locking element constraining the stagnation features in the first column, followed by the stagnation feature in the second column adjacent to the first column. The longitudinal spacing between the shaft stagnation features between features of adjacent columns is narrower than the spacing between features in a single column. Thus, resetting the accessory shaft position results in fewer incremental changes, precise changes in the shaft position than in the coarse adjustment process.

In another aspect of the present invention, a DC brushless motor having a housing, a coil assembly, a rotor, and a pie magnet assembly is provided. The coil assembly is coupled to the housing. The coil assembly has a sleeve and a plurality of windings tangled adjacent the sleeve. The winding is constructed from a wire having a generally rectangular cross section. The rotor has a bore and is rotatably coupled to the housing. The pie magnet assembly is located in the bore.

Other advantages of the present invention will be readily understood when considered in connection with the accompanying drawings, as other advantages of the present invention are better understood by reference to the following detailed description:
1 is a plan view of basic parts of a tool system according to an embodiment of the present invention.
2 is a cross-sectional view of an attachment of the tool system of the present invention including a coupling assembly.
3 is an exploded view of the deposit.
3A is a perspective view of the lock actuator integral with the attachment.
3B is a top view of the lock actuator.
4 is a cross-sectional view of the attachment of FIG. 3.
5 is an exploded view of the handpiece of the tool system of FIG. 1.
6 is a cross-sectional view of the handpiece of FIG. 5.
7 is an exploded view of the coupling assembly of the handpiece.
7A is a perspective view of the lock release ring.
8 is a cross-sectional view of the coupling assembly of FIG. 7.
8A is a first cross-sectional view of the coupling assembly collar.
FIG. 8B is a second cross-sectional view of the coupling assembly collar taken along a plane rotated 90 ° from the plane of the view in which the drawing of FIG. 8A is taken.
8C is a cross-sectional view of the handpiece bearing assembly.
9 is an exploded view of a portion and coupling of the motor rotor of the handpiece of the present invention.
Figure 10 is a cross section of a motor rotor and a portion of a coupling assembly of the handpiece of the present invention.
10A is a perspective view of the coupling assembly ratchet spring.
10B is a cross-sectional view of the ratchet spring taken along the plane including the longitudinal axis of the spring.
11 is an exploded view of the cable assembly of the tool system of FIG. 1.
12 is a cross-sectional view of the motor and cable inside the handpiece.
12A is a cross-sectional view of the stacked stack cap of FIG. 12.
FIG. 13 is a cross-sectional view of a second portion of the cable assembly of FIG. 11.
14A is a first cross section of the lock spring of the tool system of FIG. 1.
FIG. 14B is a second cross section of the lock spring of FIG. 14A.
14C is a proximal end view of the lock spring of FIG. 14A.
15A is a side cross-sectional view of the drive shaft of the tool system of FIG. 1.
15B is a side view of the drive shaft of FIG. 15A.
15C is a second cross-sectional view of the drive shaft of FIG. 15A.
16A is a side view of the cutting accessory of the tool system of FIG. 1.
16B is an enlarged view of the cutting accessory of FIG. 16A.
16C is a top view of the end of the cutting accessory of FIG. 16B.
16D is a cross section of the end of the cutting accessory of FIG. 16C.
17A is a diagram of a coil assembly in accordance with one embodiment of the present invention.
17B is a cross section of the motor of the tool system of FIG. 1.
FIG. 17C is a first view of one of the windings of the coil assembly of FIG. 17A. FIG.

1 and 2 illustrate the basic parts of the surgical instrument system 30 of the present invention. System 30 includes a handpiece 32 in which a motor 34 (shown as a phantom) is housed. Attachment 36 is rotatably and detachably fitted to the front, distal end of handpiece 32. The handpiece 32 includes a tube-shaped shell 52 that forms the outer housing of the handpiece. Collar 58 extends forward from the distal end of shell 52. Coupling assembly 38 is disposed inside handpiece 32. The coupling assembly 38 releaseably holds the accessory 40 to the rest of the system 30. Accessory 40 may be a cutting tool, saw blade, drill bit, burring device, or other type of accessory, or may provide attachment to another device (not shown). Coupling assembly 38 also transmits rotational power generated by handpiece motor 34 to accessory 40. The coupling assembly 38 also releaseably holds the attachment 36 to the handpiece 32.

Accessory 40 includes head 42. Head 42 is part of accessory 40 that is applied to the surgical site. The shaft 44 is integrally formed with the head 42 and extends rearward from the base of the head. Coupling assembly 38 transmits rotational power generated by handpiece motor 34 to accessory 40. The coupling assembly 38 and the shaft 44 are also collectively designed such that the extent to which the accessory shaft 44 extends forward of the coupling assembly is optionally set through coarse or fine adjustment (see below). This optionally allows the surgeon to adjust the extent to which the cutting accessory head 420 extends forward of the handpiece 32.

Throughout this application, “forward”, “front” and “distal” refer to the direction towards the accessory head 42, and “rearward”, It should now be understood that "rear" and "proximal" mean the direction towards the end of the handpiece 32 furthest from the accessory head 42.

A detailed understanding of the structure of the attachment 36 is achieved by initially referring to FIGS. 2 and 3. Attachment 36 includes a nose 50 and a base section 56. The nose 50 is generally tubular and thus has a bore 49 extending in the axial direction. Base section 56 is located rearward of nose 50. The base section 56 has a through bore 57 that is wider in diameter than the nose 50 and extends in the axial direction. In many versions of the invention, the nose 50 is screwed into the mating bore at the distal end of the base section bore 57 (relative bore not shown). The attachment 36 is rotated such that the run state in which the coupling assembly holds the cutting accessory 40 against rotation and the accessory 40 can be installed in the handpiece 32 or handpiece 32. The handpiece coupling assembly is moved between load states that can be removed from it. In addition, when the engagement assembly 38 is in the loaded state, the longitudinal position of the accessory 40 relative to the handpiece 32 may be selectively set through coarse or fine adjustment.

As best seen in FIGS. 2, 5, and 6, the handpiece shell 52 is generally in the form of an open tube at opposite proximal and distal ends. At the proximal end, the shell 52 has a threaded mating bore 53 (thread not shown). At the distal end, the shell 52 is formed to have a threaded mating bore 55 (thread not shown). Both mating bores 53 and 55 have diameters slightly larger than the diameter of the hollow space through the shell. The rotor 60, part of the motor 34, rotatably fits into the interior empty space of the handpiece shell 52. As best seen in FIG. 8, the rotor 60 has a cylindrical main section 62. Stem 64 extends rearward from main section 62. The stem 64 has a smaller outer diameter than the main section 62. An axially extending end closed bore 68 extends from the front end of the rotor main section 60. An axially extending bore 68 holds the pie drive magnet assembly described below. 6 and 8, it can be seen that rotor 60 is coupled to output drive shaft 76. The output drive shaft 76 is fixedly fitted to the rotor 60 by a sleeve-shaped front rotor end piece 71 in the form of a sleeve. The output drive shaft 76 is formed from a single piece of metal shaped to have a cylindrical solid stem section 78. The stem section 78 of the output drive shaft 76 is press fit into the bore of the front rotor end piece 71. The rotor end piece 71 is next press-fitted into the bore 68 of the rotor 60. This coupling arrangement ensures that the rotor 60 and the output drive shaft 76 coincide with each other.

The output drive shaft 76 is also formed to have a main section 82, which is optimally seen in FIGS. 15A and 15B, which are located at one side of the stem section 78. Stem section 78 and main section 82 are formed to have a circular cross-sectional profile. It should also be understood that the outer diameter of the output drive shaft 76 is not constant along the length of the shaft. Around the stem 78 and adjacent portions of the main section 82, the shaft 76 has a circular outer wall 137. In front of the wall 137, about the middle of the main section, the shaft 76 has a circular outer wall 139. Wall 139 has a larger diameter than wall 137. Circular outer wall 141 is the outermost circular outer wall of the output drive shaft. The wall 139 has a diameter larger than the diameter of the wall 137. The indentation processes at the opposite ends of the shaft 76 and near the proximal end of the wall 139, undercut between the walls 137 and 139 and undercut between the walls 139 and 141 are shown in FIG. 15B. Although shown, it is only relevant for reasons of manufacture.

The bearing assembly 70, optimally shown in FIGS. 6 and 8, extends between the drive shaft circular wall 137 and the inner circumferential wall of the adjacent bearing housing 80. The bearing housing 80 is a generally tubular member disposed at and extending forward from the open distal end of the handpiece shell 52. The bearing assembly 70 thus rotatably holds the front end of the rotor 60 in the handpiece shell 52. The rotor stem section 64 is rotatably held to a circular receiving plate 110 also disposed within the handpiece shell.

The output drive shaft 76 is formed with a bore 74 with an axially extending end closed from the front end of the stem section 78 and extending forward of the shaft. Bore 74 is the interior space for engagement assembly 38 in which the proximal rear end of cutting accessory shaft 44 is fitted.

3 and 4, the attachment 36 further includes a lock actuator 84, an O-ring 86, a bearing retainer 88, and a dual bearing pair 90. It can be seen that. The lock actuator 84, now described with reference to FIGS. 3A and 3B, is generally in the form of a ring and extends proximally rearwardly from the base section 56. In one version of the invention, the lock actuator 84 is screwed onto the proximal end of the base section 56. The lock actuator 84 is formed to have a pair of symmetrically opposed grooves 83 on the outer surface. Each groove 83 extends upward from the proximal end of the lock actuator 84 in a helical pattern. Each groove 83 is also formed to have a section extending downward to define a detent 85 in the lock actuator 84 at the closed distal end of the groove.

The lock actuator 84 is also formed to have a third groove, a groove 87 on the outer surface. The groove 87 extends circumferentially around the outer surface of the lock actuator 84 in front of the groove 83.

Attachment nose 50 houses cutting accessory shaft 44. The nose 50 has a tip 87 which is the foremost end of the nose. Tip 87 defines an opening into front end bore 49. Adjacent to the tip 87, the nose 50 is formed such that the bore 49 has a slightly larger diameter than the accessory shaft 44. The dual bearing pair 90 is arranged in the bore front end bore 49 such that the outer race of the foremost bearing lies against the inner annular face of the nose 50 defining the bore 49. . The dual bearing pair 90 provides a rotating fit between the accessory shaft 44 and the attachment 36. The bearing retainer 88 is a generally C-shaped member having an outer diameter larger than the diameter of the nose bore 49 prior to assembly of the attachment 36. Placing the bearing retainer 88 in the front end bore compresses and holds the retainer 88 in the front end 88. When fit within the nose 50, the bearing retainer is adjacent to the nearest position of the bearing form pair 90 to hold the pair of bearings 90 in place. The inner diameter of retainer 88 in place is smaller than the outer diameter of accessory shaft 44.

The O-ring 86 is disposed in the lock actuator groove 87. Attachment lock 84 works with collar 58 (and other components) to lock accessory 40 in place.

With particular reference to FIGS. 6, 11, and 12, it can be seen that the cable assembly 92 extends proximally from the handpiece 92. Cable assembly 92 powers motor 34 via conductor cable 96. The cable assembly 92 also includes a compression ring 98 and a collet 100. The rear cap 94 is disposed above the proximal end opening of the handpiece shell 52. The rear cap 94 includes an aperture 104 through which the cable 96 extends into the handpiece 32. The collet 100 includes a tubular skirt 101 having an outer diameter that allows the collet to slide tightly into the handpiece shell 52. Flexible fingers 106 extend proximally to the rear from the rear end of the collet skirt 101. Fingers 101 taper inwardly and are radially spaced apart from each other. The compression ring 98 has an outer circumferential surface provided with threads (not illustrated). The compression ring 98 also has a through bore 97 extending in the axial direction. The ring 98 is formed such that the through bore 97 does not have a constant diameter. Instead, the compression ring 98 is formed such that the bore 97 is tapered, and the diameter of the bore 97 is smaller at the proximal end of the ring than at the distal end. In addition, the diameter of the bore 97 along the length of the bore is slightly smaller than the diameter of the cone defined by the outer periphery of the collet fingers 106.

Once the handpiece 32 is assembled, the distal end of the cable 96 is supplied through the cap opening 104, the ring bore 97 between the collet fingers 101 and the extended front of the collet skirt 101. . The conductors inside the cable 96 are attached to the windings 108 (FIG. 17A) of the motor 34. The sub-assembly is disposed in the handpiece shell 52. The compression ring 98 is screwed into the shell counter bore 53. Rotation of the compression ring 98 causes the inner surface of the ring defining the bore 97 to compress against the collet fingers 106. The collet fingers 106 are thus tightened inwardly. As a result of the inward motion of the collet fingers 106, the fingers press and hold the cable 96 in place.

When the compression ring 98 is so secured to the handpiece shell 52, the proximal end of the ring extends back out of the proximal end of the shell. The rear cap 94 is screwed onto the exposed threaded outer surface of the compression ring 98.

A flex circuit is arranged inside the collet skirt 101. 3, the flex circuit 113 is shown assembled and folded. The flex circuit 113 has components used to control the operation of the motor 34 which is not related to the present invention. One of these parts is schematically shown as rectangular block 113a in FIG. 4. In some versions of the invention, after the handpiece 32 is partially assembled, a potting compound (not illustrated) flows into the collet skirt 101 to encapsulate the flex circuit 113.

With particular reference to FIGS. 11 and 13, the proximal end of the cable 96 is coupled to a male connector assembly 116. The male connector assembly 116 plugs into a suitable console or power source (not shown) for powering the handpiece 32. One such assembly is disclosed in Applicant's Assignee's U.S. Patent Publication No. US 2007/0250098 Al, “MOTORIZED SURGICAL HANDPIECE AND CONTROLLER FOR REGULATING THE HANDPIECE MOTOR BASED ON THE INDUCTIVELY SENSED DETERMINATION OF MOTOR ROTOR POSITION” Its contents are incorporated in this specification. In the illustrated embodiment, the male connector assembly 116 includes a cable main body 118, a male contact block 120, a flex circuit 122, a console bushing 124, Ground strap 126, washer 128, and retainer nut 130. Retainer nut 130 and bushing 120 receive the ends of the conductor cable. The component wires of the conductor cable 96 are electrically coupled to the pins 132 of the male contact block 120 through the flex circuit 122. The component pieces of the male connector assembly 116 are closed together.

The coupling assembly 38 is described in great detail. In particular, it is noted that as shown optimally in FIGS. 8 and 8C, the bearing housing 80 is shaped to have a cylindrical head 81. Threads (not shown) are formed on the outer surface of the head 81. The bearing housing 80 is shaped so that the head 81 can be screwed into the housing shell counter bore 55. The parts forming the hand piece 32 are also shaped so that when the bearing housing 80 is so secured in the cell 52, a portion of the bearing housing extends forward from the shell. The bearing housing is also formed to have a skirt 75 in the form of a sleeve extending rearward from the head 81. The skirt 75 is sized to have an outer diameter that allows the skirt to fit snugly in a hollow cylindrical space extending through the housing shell 52.

Multiple coaxial bores extend through the bearing housing head 81. The first bore, the bore 145 extends forward from the proximal end of the bearing head 81. The bore 145 is thus approached with a circular hollow space in the bearing housing skirt 75. Bore 147 extends forward from bore 145. Bore 147 has a diameter smaller than the diameter of bore 145. The third bore, bore 150 is located forward from the bore 147 and forms a distal end opening into the bearing housing 80. Bore 150 has a larger diameter than bore 145.

8A and 8B, it can be seen that the collar 58 is formed with a plurality of coaxial, constant diameter bores extending collectively end-to-end through the collar. The first bore, the bore 59 extends rearward from the distal end of the collar 58. The second bore, the bore 61 extends from the proximal end of the bore 59. Bore 61 has a larger diameter than bore 59. The third bore, bore 63 extends from the proximal end of bore 61 to form a proximal end opening into collar 58. Bore 63 has a larger diameter than the diameter of bore 61. Although not illustrated, the inner annular wall of the collar 58, which defines the bore 63, is provided with threads. Although not identified, undercuts exist for manufacturing purposes between the bore 61 and the bore 63 are illustrated.

The collar 58 is also formed to have a groove 65. The groove 65 extends in the longitudinal direction along the inner annular wall of the collar 58 defining the bore 61. A pair of oppositely opposed through holes 162 extends into the bore 59 through the collar. Inside the collar 58, there is a pair of recesses 163 in the annular wall defining the bore 59. Each recess 163 extends around a separate one of the holes 162.

When the handpiece 32 is assembled, the proximal end of the collar 58 defining the bore 63 is screwed onto a portion of the bearing housing head 81 extending forward from the shell 52.

9 and 10 provide a more detailed view of the components of the motor rotor 60 and coupling assembly 38. One or more washers 134 lie between the rotor end piece 71 and the bearings 70. The opposite side of the inner race of the bearing 70 fits against the step of the output drive shaft 76 between the circular outer wall 137 and the circular outer wall 139. The front edge of the outer race of the bearing 70 lies against the step of the bearing housing 80 between the bore 145 and the bore 147.

A ratchet spring 136 is disposed above the cylindrical outer wall 139 of the output drive shaft 76. Ratchet spring 136 is formed from a single piece of metal, such as 465 stainless steel. As can be seen by referring to FIGS. 10A and 10B, the lock spring includes a ring shaped head 186 and a ring shaped base 182 spaced forward from the head. Spiral spring element 184 extends between base 182 and head 186. More specifically, the spring element 184 can be flexibly formed such that the head 186 can be compressed toward the base 182. The ratchet spring 136 is also formed such that the base 182 has an inner diameter that causes the base 182 to be press-fitted around its shaft cylindrical outer wall 139. The ratchet spring spring element 184 and the head 186 have a common inner diameter that is larger than the inner diameter of the base 182. The larger inner diameters of the spring element 184 and the head 186 allow these parts to be moved longitudinally over the shaft cylindrical outer wall 139.

The ratchet spring 136 is also formed such that the annular distal facing surface of the head 186 is not planar. Instead, the head is formed so that the face has three conformal arc shaped steps 188, 190 and 192. Step 188 is the foremost of the steps. Step 190 is located behind step 188 and step 192 is located behind step 190. Collectively, steps 188-192 are one of the rotations of step 188, then step 190, step 190, then step 192, and step 192, then step 188. In a direction to form a circle.

Ratchet spring 136 is also shaped such that there are three identical shaped notches 194 extending inwardly from the circular inner wall of head 186. Each notch 194 extends proximally to the rear from the top of the separated one of the steps 188, 190 and 192. Thus, the notches 194 are all spaced apart from each other in the longitudinal direction. Each notch 194 is centered with respect to step 188, 190 or 192 with which the notch is associated. Each notch 194 is shaped such that the cross-sectional slice of the notch along a plane perpendicular to the longitudinal axis of the spring 136 has a curved profile. However, notches 194 are not of constant width or depth. As each notch 194 extends proximally from the top of the associated step 188, 190 or 192, both the depth and the width of the notch decrease. There are no notches 194 extending the entire length of the spring head 186, not even the notch associated with step 192.

15A and 15B, it can be seen that the output drive shaft 76 has an internal bore 138 in the main section 82. The main section 82 also includes a plurality of holes 1400. In one aspect of the invention, the main section 82 includes an odd number of holes 140. The hole 140 has a shaft outer wall ( 139. In the illustrated embodiment, the main section 82 includes first, second and third holes 140A, 140B, 140C. As shown, holes 140 Are spaced equally axially relative to the axis 142 of the output drive shaft 76. For example, three holes 140 are spaced 120 ° in the axial direction in the illustrated embodiment. Also, the holes 140 are longitudinally spaced along the axis 142. In the illustrated embodiment, the two holes 140 are not centered in the same plane perpendicular to the axis 142. No. In one embodiment, the holes 140 are spaced at a predetermined distance “d” along the axis in the longitudinal direction. It is the same distance that the upper part of the ratchet spring head edge step 188 is separated from the step 190, and the step 190 is separated from the step 192.

In FIG. 15A, the distance “2d” calls between the distal most hole 140A and the most distal hole 140C. This reflects the fact that both holes 140A and 140C are spaced at a distance d from the central hole 140B.

As best seen in FIG. 15C with respect to the holes 140B, each hole 140 is in the form of a multi-section coaxial bore (individual sections are not identified). The first section having the first diameter extends inwardly from the shaft outer circumferential wall 139. At the base of the first section there is a second transition section having a diameter tapering inwardly. The third section of constant diameter extends into the shaft bore 138 from the second section. The third section has a smaller diameter than the first section. In FIG. 15C, it is shown that the tapered, minimum diameter of the holes 140A and 140C is off-axis with respect to the sections of the largest diameter. This is because 15c is a sectional view along the central longitudinal axis of the hole 140B. Due to the holes 140A and 140C and holes 140B offset longitudinally from each other, the concentration of the bore sections forming hole 140A in FIG. 15C and the concentration of bore sections forming hole 140C Last name is not clear.

8-10, the locking elements, shown as ceramic balls 144 in the illustrated embodiment, fit into the holes 140. Each ball 144 has a diameter that allows the ball to protrude through the associated hole 140 into the shaft bore 138 but not completely pass through the hole to fall into the bore 138. (In FIGS. 6, 8 and 10, a single ball 144 is shown in only one of the holes.)

The tubular lock spring 146 is disposed over the adjacent distal end of the shaft outer circumferential wall 141 and the shaft outer circumferential wall 139. The lock spring, like the ratchet spring 136, is formed as a single piece unit and is formed from the same material from which the ratchet spring is formed. The lock spring 146, now described in detail with reference to FIGS. 14A, 14B, and 14C, has a head 202 in the form of a distal ring and a foot 206 in the form of a proximal ring. The spiral spring element 204 between the head 202 and the foot 206 allows the head and the foot to be flexible with respect to each other. The spring head 202 has an inner diameter that allows the head to be pressed onto the shaft outer circumferential wall 141 near the distal end of the shaft 76. The lock spring spring element 204 and the foot 206 have a common inner diameter that is greater than the inner diameter of the shaft outer circumferential wall 141. This relative dimensioning of the output drive shaft 76 and the lock spring 146 allows the spring spring element 204 and the foot to move longitudinally over the shaft 76.

The lock spring foot 206 is also formed such that the head 186 of the ratchet spring 136 can lie within the open end of the foot. The lock spring foot 206 is also formed to have two arc shaped toes 208 and 210 located in front of the proximal directed end of the foot and extending inwardly from the inner circumferential wall of the foot. . Each toe 208 and 210 is for an arc of 120 °. The toe 208 is located at a first distance distal in front of the proximal end of the foot 206. The toe 210 is located at a second distance in front of the proximal end of the foot 206-the second distance being longer than the first distance. Once the handpiece 32 is assembled, the distal most portion of the ratchet spring head, which defines step 188, is placed in an empty space below the lock spring toe 210. The portion of the ratchet spring 136 that defines step 190 lies in an empty space below the lock spring toe 208. The portion of the ratchet spring that defines step 192 lies in the space immediately ahead of the most proximal surface of the lock spring foot 206.

The lock spring foot 206 is also shaped to define three conformal spaced notches 214. Notches 214 extend inwardly from an inner circumferential surface of foot 206. A first notch of the notches extends distally forward from the proximal directed lower end of the foot 206. A second notch of notches 214 extends distally forward from toe 208. Third notch 214 extends distally forward from toe 210. Notches 214 are the same shape. What each notch 214 has in a plane perpendicular to the longitudinal axis of the lock spring 146 is a curved profile. From where the notch 214 is oriented, the open end of the notch, the width and depth of the notch decrease. Notches 214 are also configured to receive portions of balls 144 that protrude beyond output drive shaft 76. Also, the notches starting from the lower ends of the spring foot 206 and toe 208 do not extend forward beyond the foot. The notch starting from toe 210 extends some distance into the distal end of spring element 204 forward from the distal end of foot 206.

In addition, two arc shaped symmetrically aligned keys 216 are integral with the lock spring foot 206. The keys 216 extend proximally rearwardly from the lower end of the foot 206.

Once the handpiece 32 is assembled, the ratchet spring 136 has a sufficient length such that the spring head 186 is placed over the output drive shaft holes 140 when the spring 136 could be fully inflated. Have Similarly, the lock spring 146 has a sufficient length such that, in the expanded state, the spring foot 206 extends over the output drive shaft holes 140. The spring force of the lock spring 146 is greater than the ratchet spring 136. Thus, without any other existing force, when the springs 136 and 146 are adjacent, the lock spring 146 is sufficient to push the ratchet spring head 186 proximally away from the holes 140. Outputs

The coupling assembly 38 also includes a lock release ring 154, which is best seen in FIGS. 7 and 7A. The lock release ring 154 is formed from two semicircular sections held together by a snap ring 156. The roll release ring 154 has a central opening 220 that allows the ring to slide over the ratchet spring 136. When the bipartite is assembled together, the lock release ring 154 has a main body 222. The ring main body 222 has an outer diameter that allows the ring 154 to slide in the bore 61 inside the collar 58. The snap ring 156 lies in a groove (not identified) that extends inwardly from the cylindrical appearance of the ring main body 222. Inwardly of the main body 222, the lock release ring 154 has a step 155 recessed inwardly of the distal oriented face of the main body 222. Above step 155, the lock ring defines an empty hollow ring (space is not identified). This annular hollow space has a diameter sufficient for the proximal end of the lock spring foot 206 to be placed in the space.

The lock release ring 154 is also formed such that in step 155 there are two opposite slots 224. Slots 224 also extend some distance into the inner circumference of ring main body 222. Each slot 224 is sized to receive a separate one of the lock spring foot 206 and the integral keys 216.

The cylindrical outer surface of the lock release ring main body 222 is formed with a bore 226 with an end closed. Bore 226 is shaped to partially receive the spherical bearing 158 shown in FIGS. 7 and 8. A portion of the bearing 158 that extends beyond the ring 154 lies in a groove 65 inside the collar 58. Both the collar 58 and the lock release ring 154 and the confinement of the bearing 158 thus allow the ring to move longitudinally within the collar bore 65 while preventing the ring from rotating.

A wave spring 152, which is also part of the coupling assembly 38, is disposed above the ratchet spring 136. The wave spring 152 has a diameter that allows the spring to fit within the bore 150 within the bearing housing 80. The proximal end of the wave spring 152 lies against the distal facing surface of the bearing housing 500 which defines the base of the bore 150. The distal end of the wave spring 152 is proximal to the lock release ring 154. Is placed on the face

Once the handpiece 32 of the present invention is assembled, the lock release spring 146 and the wave spring 152 act on opposite sides of the lock release ring 154. The parts are selected such that the wave spring 154 exerts a greater force than that exerted by the lock spring 146. Thus, when the handpiece 32 is assembled, the wave spring 152 draws the lock release spring 154 and, by extension, pushes the lock spring 146 forward. The forward movement of these parts is stopped by the abutment of the distal oriented face of the lock release ring 154 with respect to the annular step between the calibres 59 and 61.

Two opposite bushings 160, optimally shown in FIGS. 7 and 8, are rotatably mounted in the collar bore 51. Each bushing 160 is rotatably mounted to a pin 159. The stem of each pin 159 fits into a separate one of the collars through the holes 162. Each bushing 160 partially lies in and extends outwardly from a recess 163 in the interior of the collar 58 surrounding each hole 162. The bushings 160 are sized to move in grooves 83 formed in the lock actuator 84.

The structure of the handpiece motor 34 is now discussed in more detail with an initial reference to FIG. 17B. The motor 34 is a 4-pole, brushless sensorless DC motor. Four magnets 72 are disposed in the rotor bore 68. Each magnet 72 is generally in the form of a pie slice facing an arc of 90 °. The north-south pole alignment of each magnet is such that one pole is located in the corner, the two sides of the magnet meet and the opposite pole is located along the curved outer surface of the magnet. The magnets are arranged collectively so that the two magnets with the north pole on their outer circumferential surface are aligned opposite to each other. Thus, along their outer circumference the magnets 72 with the south pole are similarly aligned oppositely.

Motor 34 also includes a lamination stack and a set of windings 108. The stack stack 170, now described with reference to FIGS. 6, 11 and 12, is a series of soft magnetizable materials (individual washers are not identified) stacked one on top of each other. It is made of a washer-shaped material. Stack stack 170 is disposed above the section of rotor 60 in which windings 108 are disposed. The stack stack 170 is shaped such that when disposed over the rotor 60, there is an annular void space between the rotor and the stack stack.

The proximal end of the lamination stack lies in the stack end cap 240, which is best seen in FIGS. 12 and 12A. Cap 240 is formed from plastic. Cap 240 consists of inner and outer coaxial sleeves 242 and 248, respectively. The inner sleeve 242 has an unidentified, through bore having a diameter larger than the diameter of the rotor stem 64. At the proximal end of the inner sleeve 242, a washer shaped web 246 extends outwardly to connect the sleeves 242 and 248 together. Outer sleeve 248 extends over inner sleeve 242 and is radially spaced from inner sleeve 242. The outer sleeve 248 has a diameter that allows the sleeve 248 to be tightly slipped into the handpiece shell 52. The outer sleeve 248 also extends forward from the web 246 a longer distance than the distance that the inner sleeve 242 extends away from the web. Stack end cap 240 is further formed to have counter bore 249 in the open end of outer sleeve 248.

Stack end cap 240 is also formed such that a number of rigid tubes 250 extend through web 246. In the described version of the invention, there are three tubes 250 equally spaced about the longitudinal axis of the stack end cap 240. (Only two tubes 250 are shown in FIG. 12A.) Each tube 250 extends rearward away from the proximal oriented end face of the web 246. The tubes 250 function as a conduit through which the conductors integral with the cable 96 pass, so that the conductors can be connected to the motor winding 108.

Once the handpiece 32 is assembled, the proximal end of the cap web 246 is disposed with respect to the surface facing away from the receiving plate 110. Cap tubes 250 extend through openings 251 in the receiving plate. In FIG. 12 only a single opening 251 is shown. Rotor stem 64 extends through an empty space in the center of inner sleeve 242. The proximal end of the stack stack 170 lies in the mating bore 249 of the outer sleeve 248.

In FIG. 12, a ring shaped circuit board 243 is disposed around the distal end of the cap inner sleeve 242. Circuit board 242 supports the components used to regulate the operation of handpiece motor 34.

The distal end of the stack stack 170 lies within the stack front cap 252. Stack front cap 252 is from a single piece of plastic and is open at both ends. The cap 252 is formed to have a base 254. The base 254 has an outer diameter that allows the stack front cap 252 to be in close sliding fit within the handpiece shell 52. In front of the base 254, the cap 252 has a head 256 in the form of a ring. Head 256 has a smaller outer diameter than base 254. Two bores, bore 258 and bore 260 extend axially through cap 238. Bore 258 extends forward from the distal end of cap base 254 partially through the base. Bore 260 extends from the distal end of bore 260 through the distal portion of base 254 and the entirety of cap pad 256. Bore 260 has a smaller diameter than bore 258.

When the handpiece 32 of the present invention is assembled, the stack front cap head 256 is disposed against the circular inner wall of the bearing housing scud 75. The distal end of the stack stack 170 lies within the cap bore 260.

Winding 108 is disposed in an annular hollow guide between rotor 60 and lamination stack 170. In the illustrated version of the present invention, there are six windings 108A-108F. 17C is a depiction of a single winding 108. The winding is formed from a wrap of wire 102. In more detail, wire 102 is a wire having a rectangular cross-sectional profile. In one version of the invention, the wire 102 forming the winding 108 has a side to side width between 0.13 and 0.38 mm and a top to bottom height between 0.51 and 1.3 mm. Wire 102 is wrapped such that each winding 108 is generally in the form of a rectangular frame with rounded corners. Each winding 108 is made up of multiple overlapping turns of wire 102. The wire is looped so that the broadly surfaced top and bottom surfaces of the wire are adjacent. As shown in FIG. 17C, due to the structure of the windings 108, each winding defines three empty spaces 108 positioned centrally. Opposite ends of each section of the wire forming the winding 108 are winding leads 111.

Although not illustrated, it should be understood that an insulating coating is disposed over the wires 102 forming the winding 108.

By referring to FIGS. 17A and 17B, it can be seen that when the handpiece 32 is assembled, the windings 108A-108F are positioned relative to the annular inner surface of the washers forming the stack stack 170. have. The windings are arranged to interleave with each other. Thus, the elongated side of one of each of the windings 108D and 108E is disposed in an empty space 109 between the elongated sides of the winding 108A. Similarly, the first of the sides of the cage of the winding 108A is disposed in the empty space 109 between the sides of the winding 108D. The second of the three sides of the winding 108A is disposed in the empty space 109 between the three sides of the winding 108E.

When the handpiece 32 is assembled, opposite upper and lower ends of the windings extend from the distal and proximal ends of the stack stack 170, respectively. Winding leads 111 extend from the rear proximal end of the stack. It is in this space behind and ahead of the stack of stacks that cross over each other such that the windings 108 are interleaved. Although not illustrated, it should be understood that the winding leads 111 are connected to conductors integral with the cable 96. In addition, when assembling the handpiece 32, a small annular gap, the rotor 72, is disposed between the inner surfaces of the windings 108 and the rotor main section 62. It should be understood that there is a section of (60).

The structure of the cutting accessory shaft 44 is now described by referring to FIGS. 16A-16D. Generally, accessory shaft 44 has a cylindrical shape. The shaft is still shaped to have a tip 272 that is tapered in its proximal end, though. More specifically, the distal end of the shaft tip 272, which is the distal end of the cutting accessory 40, is a flat surface and has a diameter smaller than the diameter of the main body of the shaft 44. Tip 272 is conical in shape and has an outer circumferential surface that is tapered outward toward the diameter of shaft 44.

Located in front of tip 272, accessory shaft 44 is shaped to have a number of stagnation features 274. In the illustrated version of the present invention, each stagnation feature 274 is in the form of an indentation in the shaft. Each stagnation feature 274 includes a central face 280 that is concave with respect to the outer surface of the accessory shaft. Each central face 280 is bent around an axis perpendicular to the longitudinal axis of the shaft 44. The common radius of curvature of the stagnation feature central face 280 is smaller than the radius of the balls 144. Each stagnation feature also includes a pair of opposed facets 278 extending from opposing proximal and distal facing sides of the associated central face 280. Each facet 278 is angled upward from the associated flat 274 to the outer surface of the accessory shaft. The length of each stagnation feature 274 between the ends of opposing facets 278 is sufficient to accommodate at least a portion of the balls 144 in the void space between the facets.

The stagnation features 274 are arranged in a plurality of angularly spaced columns on the accessory shaft. In the section of the “unwrapped” shaft shown in FIG. 16C, the shaft is shown to have six columns 280, 282, 284, 286, 288, 290 of stagnation features. There are a plurality of stagnation features in each column 280-290 of stagnation features. In the illustrated version of the present invention, columns 280-290 of stagnation features are equidistant from each other.

In the illustrated version of the present invention, the stagnation features 274 of each column 280-290 of stagnation features are longitudinally spaced from each other. For example, in one version of the present invention, each stagnation features have a longitudinal length “e” of about 2.1 mm, and the spacing “f” between two adjacent longitudinally aligned stagnation features is about 0.9 mm. Thus, the distance between the axes next to two adjacent longitudinally aligned stagnation features is 3.0 mm. This distance is understood by way of example and not limitation.

The cutting accessory 40 of the present invention is also configured so that stagnation features of adjacent columns are not aligned next to each other. Here, "aligned laterally" is understood to mean aligned along an axis perpendicular to the longitudinal axis of the shaft 44. Instead, radially adjacent columns, such as adjacent stagnation features 274 of columns 284 and 286, are at different distances relative to the proximal end of accessory shaft 244. The angled and longitudinal spacing of the stagnation features between adjacent columns gives the appearance that the stagnation features 274 are arranged spirally around the shaft 44.

In the illustrated version of the present invention, stagnation features in one column are adjacent columns by a distance equal to one-sixth of the longitudinal distance whose side axis separates adjacent stagnation features in a single column of stagnation features. Positioned so as to be longitudinally offset from the axis next to the stagnation features within. Thus, in FIG. 16C, stagnation features 274B in column 284 are spaced at a distance of 0.50 mm above adjacent stagnation features 274A of adjacent columns 282. In addition, stagnation features 274B are spaced at a distance of 0.5 mm below adjacent stagnation bodies 274C of adjacent columns 286. This distance is related to the longitudinal distance d between the holes 140A, 140B and 140C of the output drive shaft 76. More specifically, the longitudinal spacing between the stagnation features 274 of adjacent columns of stagnation features is one half of the longitudinal distance d between the holes 140A, 140B and 140C. The logic behind this relationship will be clearly described below.

It can also be seen from FIG. 16C that the stagnation features 274 of adjacent columns of stagnation features, eg, the features of columns 284 and 286 partially overlap each other.

Initially neither attachment 36 nor accessory 40 is attached to the handpiece 32 of the present invention. When handpiece 32 is in this state, wave spring 152 holds lock release ring 154 in its fully distal forward position, such that ring 154 is collared as shown in FIG. 8. The annular step between the bores 59 and 61 abuts. Due to the distal forward driven lock release ring 154, the proximal end of the lock spring foot 206 abuts step 155 integral with the lock release ring. The spring force of wave spring 152 is greater than lock spring 146. Thus, the wave spring 152 not only holds the lock release ring in the foremost position, but also the wave spring allows the lock release ring 154 to move the lock spring foot 206 away from the holes 140 in the drive shaft. Provide enough force to hold.

Because the lock spring foot 206 is held away from the holes 140, the ratchet spring 136 can be inflated above the output drive shaft 76. The ratchet spring head 186 thus extends around the holes 1400. When the spring head 186 is in this position, each exposed section of the balls 144 is notched inside the spring head 186. In each one of the fields 194. More specifically, the distal most hole, the ball 144 disposed in the hole 140A, lies in the notch 194 associated with the distal most step, step 188. The ball 144 in the intermediate hole 140B lies in the groove 194 associated with the intermediate step 190. The ball associated with the nearest hole 140C lies in the groove 194 of the proximal step 192. As a result of the spring head 186 surrounding the balls 144, the balls receive a blocking force that prevents the balls from falling out of the holes 140 and from the output drive shaft 76. However, for the reasons described below, Ratchet spring 136 prevents balls from being pushed out of shaft bore 138 Groups do not exert sufficient force. Are considered to be in a coupling assembly 38 that when in this state, the coupling assembly 38 is loaded state (load state).

When the engagement assembly 38 is in the loaded state, the lock release ring 154 pushes the lot spring foot 206 further forward. As a result of the lock release ring 154 contacting the lock spring foot 206, keys 216 integral with the spring foot are placed in the slots 224 inside the lock release ring. As noted above, while the lock release ring 154 can move longitudinally relative to the other parts of the handpiece 32, the ring is blocked from rotation. Thus, when the handpiece is in the loaded state, key-in-slot mating of the lock spring to the lock release ring prevents spring rotation by extension of the output drive shaft 76. . This component confinement prevents accidental actuation of any accessory and output drive shaft fitting to the shaft unless the coupling assembly is in a run state.

The system 30 of the present invention is ready for use by first placing the front end attachment 36 over the handpiece 32. Nevertheless, the attachment 36 is not fully inserted into the handpiece collar 80. Instead, the attachment 36 fits over the handpiece 32 such that the handpiece collar bushings 160 only partially exit through the actuator grooves 83. At this time, while the proximal end of the attachment lock actuator 84 is in contact with the lock release ring 154, the lock actuator does not displace the lock release ring. Also at this time, the attachment O-ring 86 extends into the collar bore 59. The outer surface of the o-ring 86 abuts the adjacent annular wall of the collar 80 defining the bore 59 to establish a passively releasable friction fit between the attachment 36 and the handpiece 32. do.

Attachment 36 is partially secured to handpiece 32 so accessory 40 is then inserted. An accessory shaft 44 is inserted through the attachment such that the proximal tip 272 of the shaft enters the output drive shaft bore 138. Ultimately, the tapered surface of the tip 272 abuts the portions of the balls 144 held in the bore by the ratchet spring 136. Due to its tapered profile, as the shaft tip 272 is pushed inward, the tip can push the balls 144 outward, overcoming the force of the ratchet spring 136.

As the shaft is moved proximally, each ball 144 moves from and within stagnation features 274 forming each one of the columns of stagnation features 280-292. . More specifically, balls 144 lie in alternating columns of stagnation features. Thus, the balls 144 lie within the stagnation features of the columns 280, 284 and 288 or the stagnation features of the columns 282, 286 and 290. As the shaft 44 is pushed into or pulled out of the shaft bore 138, displacing the shaft individually causes ratcheting as the balls move in and out of the stagnation features. The amount of force the spring 136 imposes on the balls 144 overcomes the change. Exposure to this changing force provides tactile feedback that the balls 144 lie within different sets of stagnation features 274.

It should also be understood that when the engagement assembly ball 144 lies within the shaft stagnation feature 274, the ball does not lie completely against the surfaces of the stagnation feature. That is, the ball abuts opposite facets 278 of the stagnation feature. Thus, individual ball-retention feature contacts follow opposite sections of the circle. This design feature allows the manual force needed to overcome the force of the ratchet spring 136 to be established with some precision.

During this process, there are two ways in which the length that the cutting accessory 40 extends forward from the handpiece 32 can be selectively set. By pushing the accessory 40 in a straight line inward or pulling the accessory 40 in a straight outward, each ball 144 is moved out of columns 280, 282, 284, 286, 288 or 290 of stagnation features. It sits in turn on the identity features of a single column. Each time, the balls 144 move from the set of stagnation features and into the set of stagnation features, the shaft moving a distance equal to the distance between the centers of adjacent stagnation features of a single column of stagnation features. This adjustment of the shaft extension / contraction is a rough adjustment of the accessory extension.

Alternatively, accessory shaft 44 can be rotated helically. When shaft 44 is so rotated, balls 144 are integral with columns 282, 286, and 290 from being located in stagnation features 274 integral with columns 280, 284, and 288. Replace with congestion features. As noted above, the longitudinal separation between stagnant features of adjacent columns of features is 0.5 distance d. Since the longitudinal distance between the balls of the holes 140A, 140B and 140C is the distance d, the balls may be located in the stagnation features of alternating columns of stagnation features. Again, stagnation features of adjacent columns are longitudinally offset from each other by the distance of internal column separation of one sixth of adjacent stagnation features. Thus, each rotation of the shaft by 60 ° results in extension or contraction of the shaft by a distance equivalent to one sixth of the longitudinally aligned stagnation features forming a single column of stagnation features. For example, by rotating the shaft 44 helically, the shaft is positioned where the balls 144 rest on the stagnation features 274D, 274E, and 274F associated with the columns 280, 284, and 288, respectively. From, the balls can be displaced to a position that lies in stagnation features 274G, 274H and 274I. These latter stagnation features 274G, 274H, 274I (shown in phantom in FIG. 16C) are associated with columns 282, 286 and 290, respectively. This adjustment of accessory shaft 44 extension / contraction is a precise adjustment of the accessory extension. In the described version of the invention, the fine adjustment is therefore 0.5 mm in contrast to the rough adjustment of 3.0 mm.

Once the position of the accessory shaft 44 is set, the coupling assembly 38 is in a run state. This operation is performed by rotating the attachment 36 helically such that the lock actuator 84 is pushed proximally toward the handpiece motor 36. Attachment 80 is rotated until engagement assembly bushing 160 lies over distal end of lock actuator slots 83, over detent 85. As a result of the proximal displacement of the attachment 36, the lower surface of the lock actuator 83 pushes the lock release ring 154 proximally. In other words, the force exerted by the individual in rotating the attachment 84 is sufficient to overcome the force exerted by the wave spring 152 to hold the lock release ring 154 in the distal position.

As a result of the rearward displacement of the lock release ring 154, the lock spring 206 is free of expansion. The lock spring spring element 204 pushes the spring foot 206 proximally. Because the lock spring spring element 204 has more spring force than the ratchet spring spring element 184, the lock spring foot 206 has a ratchet spring away from the section of the shaft 76 in which the holes 140 are formed. Push the head 186. Lot spring foot 206 extends over holes 140. More specifically, the lock spring 146 is configured such that when the spring foot 206 proximally extends rearwardly, each of the balls 144 lies in one of the notches 214 formed in the foot (the output drive shaft). Fits 76). Specifically, the ball 140 lying in the distal most shaft hole 140A lies in the notch 214 associated with the toe 210. The ball 140 lying in the middle hole 140b lies in the notch 214 associated with the toe 208. The ball 144 lying in the most recent hole 140C lies in a notch 214 extending forward from the most upright end of the spring foot 206.

The lock spring 146 is also configured such that the spring element 204 withstands the tangential forces that the cutting accessory shaft 44 imposes on the engagement assembly balls 144. Thus, when the spring foot 206 is placed over the coupling assembly balls 144, the coupling assembly holds the assembly cutting accessory 40 so that the accessory moves in line with the handpiece output drive shaft 76. Can be considered to be in a running state.

The displacement of the lock release ring 154 from the lock spring foot 206 is done farther than allowing the lock spring to lock the cutting accessory 40 to the handpiece output drive shaft 76. As a result of the backward movement of the lock release ring 154 from the lock spring foot 206, the foot keys 216 are freed from the lock ring slots 224. This disengagement of the lock spring 146 from the lock release ring 154 causes the spring 146 and, by extension, causes the output drive shaft 76 to operate the motor 34. When it is free to rotate.

When the engagement assembly 38 is in the run state, the lock release ring 154 continues to apply pressure against the lock actuator 84 to push the attachment 36 forward. As a result of this displacement of the attachment 80, the handpiece bushings 80 lie at the ends of the lock actuator grooves 83, below the edges of the adjacent detent 85. This placement of the bushings 160 in the distal end of the grooves 83 secures the attachment 36 to the handpiece 32 releasably.

During operation of the system 30, the attach O-ring 86 serves as a seal that prevents the fluid to which the system is exposed flows between the attach 36 and the handpiece collar 58.

Once attachment 36 and cutting accessory 40 are locked to handpiece 32, the surgeon can reset the extent that attachment shaft 44 extends forward from the handpiece. This adjustment is effected by pushing the attachment 36 down and then rotating so that the attachment moves forward from the handpiece collar 58. Wave spring 152 pushes attachment 36 forward through lock release ring 154. The friction imposed by the O-ring 86 prevents the force output by the wave spring 152 from pushing the attachment 36 completely out of the collar bore 59. However, the lock release ring 154 is displaced forward enough distance so that the ring 154 moves the lock spring foot 206 away from the shaft holes 140. The engagement assembly 38 returns to the loaded state to allow extension or retraction of the accessory shaft 44. Once the position of the accessory 44 is reset, the attachment 36 is rotated back down on the handpiece 32 to return the coupling assembly 38 to the run state.

It is to be understood that the foregoing is for one specific version of the present invention. Other versions of the invention may have different features than those described. For example, there is no requirement that all versions of the present invention have the motor 34 described.

Thus, other versions of the present invention with alternative electric motors are possible. It is likewise possible to configure this version with pneumatic or hydraulic motors.

Likewise, alternative versions of the invention may be provided with different coupling assemblies than those described in detail. For example, in some versions of the present invention, locking elements other than balls may be employed to hold the accessory shaft to the handpiece output drive shaft. Thus, in some versions of the invention, a collet with spring loaded foots can perform this function. In these versions of the invention, the collet foots extend into the output drive shaft bore to function as a locking element. In these and other versions of the present invention, the natural tendency of the spring to keep the collet foots in the bore can eliminate the need to provide a ratchet spring to hold the feet (locking elements) in place. .

In addition, in all versions of the invention, there is no requirement that three locking elements exist. There are generally at least two conformally spaced locking elements to prevent lateral loading of the accessory shaft 44. However, some configurations of the coupling assembly may require only a single locking element. In other versions of the invention, there may be four or more locking elements.

Likewise, in all versions of the present invention, there is no requirement that the lock actuator leaving the coupling assembly 38 loaded is part of the detachable attachment. In some embodiments of the present invention, such a lock actuator, which may even be in the form of a ring, may movably fit into the handpiece. When the surgeon wishes to transition the engagement assembly between the rod and run states, the drive member, such as a button, on the handpiece is displaced. The displacement of the drive member connected to the lock actuator results in similar displacement of the lock actuator causing the required load state / run state transition of the coupling assembly.

It should then be understood that in some versions of the invention, the spring is not employed as a lock member that selectively holds the lock elements in the run position. In some versions of the invention, a ring or sleeve that is manually displaced between the rod position and the run position performs this function.

In some versions of the above embodiment of the present invention, the handpiece may not even be designed to receive attachments. In alternative versions, a second engagement assembly is used to releaseably attach the attachment to the handpiece.

Likewise, it should be understood that the above-described coupling assembly comprising an attachment may even be included in the attachment. Thus, in this embodiment of the invention, the attachment has its own output drive shaft. The engagement assembly enables the above coarse or fine adjustment of the range in which the accessory shaft extends forward from the attachment.

Similarly, it should be understood that the engagement assembly locking elements complementary to the accessory retention features may have a different geometry than described. In some versions of the invention, the accessory stagnation features may even be tabs or other members extending outward from the surface of the accessory shaft 44. In some versions of the invention, the stagnation features may be V-shaped, W-shaped or partially spherical or circular indentations in the accessory shaft. In these versions of the invention, the handpiece engagement assembly locking elements are shaped to lie on or within these features.

In addition, in some versions of the invention, the stagnation features in a single column of stagnation features may not be spaced apart from each other. Thus, along the proximal or distal shaft where one stagnation feature ends, another stagnation feature begins. Similarly, in the described version of the present invention, the stagnation features 274 in adjacent columns of stagnation features partially overlap. In some versions of the invention, there may be some radial separation between adjacent columns of stagnation features. In some versions of the invention, stagnation features in adjacent columns of stagnation features may not overlap longitudinally with each other.

It should also be understood that in some versions of the system 30 of the present invention, the ratio of the handpiece coupling assembly locking elements to the columns of the shaft stagnation features may differ from the 1: 2 ratio described. In some versions of the invention, this ratio may be 1: 1. Thus, with respect to versions of the invention with three locking elements, each 120 ° spiral turn of the shaft will result in shaft length fine adjustment, which is one third of a single rough adjustment. Alternatively, the ratio may be greater than 1: 2. For example, in the present invention system where the handpiece coupling assembly has two locking elements, the shaft may have eight stagnation features every 360 ° turn of the shaft. In this version of the invention, 45 ° rotation of the shaft will result in precise adjustment of shaft extension or contraction, which is one eighth of a single coarse adjustment.

Likewise, the actual tissue work member at the distal end of the cutting accessory shaft 44 may be different from the burr heads described and illustrated.

Other surgical handpieces of the present invention may have some or all of the features of the described motor 34 and the coupling assembly having different features than described. Thus, the handpiece of the present invention may have an alternative winding arrangement and magnets having a pie sliced form as described. Likewise, some handpieces of the present invention may have magnets inside the rotor of different designs in addition to the windings described. Multiple rotor magnets and stator windings may also differ from that described.

Likewise, in some versions of the invention, the wires that form the windings of the motor 34 may have, in cross section, two opposed surfaces that are planar and side by side. Likewise, in still other versions of the present invention, the wires may be rectangular in cross section, but they may not be rectangular.

In all versions of the present invention, there is no requirement that the output drive shaft is firmly attached to the motor rotor 60. In some versions of the present invention, a gear assembly, not illustrated, may serve as an interface between the motor rotor and the output drive shaft 76. Depending on the configuration of the gear assembly, this assembly can increase or decrease the rotational speed of the output drive shaft relative to that of the motor rotor.

Accordingly, it is the object of the appended claims to cover all such variations and modifications as fall within the true spirit and scope of the present invention.

Claims (21)

As a cutting accessory 40 for use with a powered surgical handpiece,
An elongated shaft 44 having opposed proximal and distal ends;
A tissue working member 42 attached to the distal end of the shaft; And
A plurality of retention features formed in the shaft in front of the proximal end and arranged in columns 280, 282, 284, 286, 288, and 290 extending longitudinally along the shaft; 274, wherein each column comprises a plurality of longitudinally spaced stagnation features, wherein the columns of stagnation features comprise a plurality of stagnation features radially spaced from one another,
The stagnation features are longitudinally offset from stagnation features 274G, 274H, 274I in the radially adjacent column of stagnation features in the column of stagnation features 274D, 274E, 274F. Cutting accessories, characterized in that also formed on the shaft (44). The method according to claim 1,
Wherein each stagnation feature (274) is an indentation of the shaft (44). The method according to claim 1 or 2,
The cutting accessory in each column (280, 282, 284, 286, 288, 290) of the stagnation features (274), wherein the longitudinally adjacent stagnation features are longitudinally spaced from each other. The method according to any one of claims 1 to 3,
At the proximal end of the shaft 44 there is a tip 272, which tip has a form tapering outwardly toward the outer circumference of the shaft while extending distally along the tip. Cutting accessories. The method according to any one of claims 1 to 4,
And the tissue work member (42) is a bur. As a powered surgical handpiece 32,
A housing 52;
A motor (34) disposed in the housing and having a rotor (60);
An output drive shaft 76 connected to the motor rotor for rotation by the motor rotor, the elongated bore 138 sized to receive the shaft 44 of the cutting accessory 36. An output drive shaft 76 having a;
A plurality of radially spaced locking elements 144 disposed around the output drive shaft extending into the bore to engage complementary stagnation features 274 formed in the cutting accessory shaft. A locking element 144 such that when the locking elements are constrained, the output drive shaft and the cutting accessory are rotated in correspondence; And
Bringing the locking elements into the output drive shaft bore 138 such that the locking elements bind the cutting accessory stagnation features 274 and allow the locking elements to be pulled out of the cutting accessory stagnation features. A lock assembly 84, 146, 152, 154 disposed on the output drive shaft 76, which optionally holds;
The locking elements 144 extend into the shaft bore 138 at longitudinally spaced locations along the shaft bore 138 and are arranged around the output drive shaft 76. Handpiece. The method of claim 6,
In the output drive shaft 76 a plurality of apertures 140A, 140B, 140C are located, in which the locking elements 144 are located and the locking elements extend therethrough into the shaft bore 138. Wherein the holes are longitudinally spaced from one another along the shaft (76) and radially spaced from each other. The method according to claim 6 or 7,
The locking elements 144 are ball shaped, powered surgery handpiece. The method according to any one of claims 6 to 8,
The handpiece has a distal end, and the output drive shaft 76 proximally extends rearwardly from the distal end of the hand piece;
A powered surgical handpiece with an attachment (36) detachably attached to the distal end of the handpiece, the attachment having bores (49, 57) through which the cutting accessory shaft (44) extends. The method according to any one of claims 6 to 9,
At least one component (84) of the lock assembly is part of an attachment (36) detachably attached to the handpiece housing (52). The method according to claim 10,
The handpiece and the attachment 36 are assembled such that the attachment has a first state when the attachment is initially coupled to the handpiece and a second setting when the attachment is finally coupled to the handpiece. Arranged in a way;
The lock assembly 84, 146, 152, 154 allows the lock assembly to cause the locking elements 144 from the cutting accessory stagnation features 27 when the attachment is initially coupled to the handpiece. And allow the lock assembly to hold and lock the locking elements with the cutting accessory stagnation features when the attachment is finally coupled to the handpiece. The method according to any one of claims 6 to 11,
The lock assembly 84, 146, 152, 154 allows the locking elements 144 to be pulled out of the cutting accessory stagnation features to inhibit rotation of the output drive shaft. Is positioned, the lock assembly is positioned to bind and hold the locking elements with the cutting accessory stagnation features to constrain the output drive shaft 76 and to enable rotation of the output drive shaft. And when configured to disengage the output drive shaft. The method according to any one of claims 6 to 12,
When the lock assemblies 84, 146, 152, 154 allow the locking members to be pulled out of the cutting accessory stagnation features 274, the locking elements 14 are moved to the output drive shaft bore. A powered surgical handpiece, further comprising a biasing member 136 that holds within 138. The method according to any one of claims 6 to 13,
The lock assembly includes a first spring element 146 disposed over the output drive shaft that provides a force to hold and lock the locking elements 144 with the cutting accessory stagnation features 274. Motorized surgical handpiece. The method according to claim 14,
The lock assembly releases the first spring element 146 to unbond the first spring element 146 from holding and holding the locking elements 144 with the cutting accessory stagnation features 274. A release member (154) movable relative to the first spring element (146), which is positioned to selectively abut). The method according to claim 14 or 15,
The lock assembly holds the first spring element 146 in a position where the first spring element 146 does not bond with the cutting accessory stagnation features 274 to hold the locking elements 144. To include a second spring element (152) acting on the first spring element (146). The method according to any one of claims 6 to 16,
The motor 34 is a powered surgical handpiece, either an electric motor or a pneumatic motor. As a powered surgical handpiece 32,
A housing 52;
An electric motor (34) disposed in the housing and having a rotor (60);
An output drive shaft 76 connected to the motor rotor for rotation by the motor rotor, the output drive shaft 76 having an elongate bore 138 sized to receive the shaft 44 of the cutting accessory 36; And
Extend into the shaft bore 138 to constrain the complementary stagnation features 274 formed in the cutting accessory shaft such that the output drive shaft and the cutting accessory are rotated coincidentally when the locking elements are constrained. A coupling assembly 84, 146, 152, 154 disposed above the output drive shaft with locking elements 144,
A bore (68) is formed in the motor rotor;
Power surgical handpiece, characterized in that at least two magnets (72) are encased in the rotor bore and arranged to abut one another in the bore. The method according to claim 18,
The motor 60 includes an even number of magnets 72 and at least four magnets, each magnet having a cross-sectional shape such that one of the poles of the magnet is in the corner, the magnets being the Power surgical handpiece, arranged in the rotor bore (68) so that the corners of the magnets abut. As a powered surgical handpiece 32,
A housing 52;
An electric motor 34 disposed in the housing,
Rotor 60;
A lamination stack 170 disposed around the rotor, the lamination stack 170 formed from a magnetizable material; And
A winding assembly disposed between the lamination stack and the rotor, the winding assembly comprising a plurality of windings 108,
Electric motor 34;
An output drive shaft 76 connected to the motor rotor for rotation by the motor rotor, the output drive shaft having an elongate bore 138 sized to receive the shaft 44 of the cutting accessory 36; And
Extend into the shaft bore 138 to constrain the complementary stagnation features 274 formed in the cutting accessory shaft such that the output drive shaft and the cutting accessory are rotated coincidentally when the locking elements are constrained. A coupling assembly (84, 146, 152, 154) disposed above the output drive shaft with locking elements (144);
Wires 108 of the winding assembly are formed from coils of wire, the wires having at least two opposing planes in a cross sectional profile with each said coil flanked (side sections) and individual coils wound to have a void space 109 therebetween, the windings having the sides of each of the windings having the empty spaces of the windings on both sides of the winding. A powered surgical handpiece, characterized in that it is arranged to be disposed within. The method of claim 20,
Wherein the wires of the assembly have a rectangular cross-sectional profile.

Images